The S.O.L. Meter, which stands for the Speed Of Light Meter, is an important device that should be integral to every vehicle, whether motorized or not. Its aim is to inform the driver of the fraction of the speed of light the vehicle is traveling, so that the driver will be able to account for special relativity effects. Without a knowledge of when to take special relativity effects into account, a driver could be confused by such phenomena as length contraction, time dilation, and in some cases, causality paradoxes. A quick summary of special relativity can be found at Einstein Light [1]. Naturally, any of these effects could be disastrous in environments such as Interstate 95 or the Autobahn.

Currently, not much attention is being paid to the s.o.l. meter. After the discovery of the complicated voltage-to-speed function of the speedometer leads, and the failure to find a suitably accurate square-rooting circuit that can be reliably built, it was decided that taking the speed input from a different location would be necessary. However, this has not yet been done. It is likely that the best place to find this information is directly from the wheel sensor.